1. Field of the Invention
The present invention relates to an image processing device and image processing method, and program, and specifically, relates to an image processing device and image processing method, and program whereby a block size and block border position can be detected with high precision even in the case that scaling is performed with an arbitrary scaling factor.
2. Description of the Related Art
In the event of decoding encoded image data, noise may occur in the decoded image. For example, in the event of compressing image data with a compression method such as MPEG (Moving Picture Experts Group), an encoder divides the image data into square blocks made up of multiple pixels, and subjects each divided block to DCT (Discrete Cosine Transform) processing.
Therefore, when a decoder decodes the image data encoded with the MPEG method, in principle with the decoded image data, pixel value levels between pixels can may differ at border portions of each block, whereby block noise can readily occur.
A device to reduce or remove such block noise generally does so by applying an LPF (Low Pass Filter) over a known block size (e.g. 8 pixels×8 pixels if MPEG2) and at block border positions, and smoothing. However, for such smoothing, information of the input image data such as block size and block border position has to be available beforehand.
Accordingly, a technique has been proposed wherein cyclic nature is used in order to realize such processing to obtain the block sizes and block border positions in the input image (Japanese Unexamined Patent Application Publication No. 2007-028460).
Also, a method has been proposed wherein cyclic nature is not used, but block noise feature is used to perform determination of a block border, cumulatively process results obtained by subjecting the determination results thereof to weighting according to the level thereof, in a spatial direction, and detect a block border position according to the cumulative results thereof (Japanese Unexamined Patent Application Publication No. 2005-012641).